Process of producing tetra-substituted ureas



Patented Nov. 28, 1922.

UNITED STATES WARE.

PATENT OFFICE.

ELAWARE. ASSIGNOR T0 E. I. DU PONT DE N. DELAWARE. A CORPORATION OF DELA- PROCESS OF PRODUCING TETRA-SUBSTITUTED UREAS.

N0 Bra wing.

To all whom it may concern:

Be it known that I. Aernnn P. TANnEno, of \Vilinington, in the count of New (astle and in the State of Delaware. have invented a certain new and useful Improvement in Processes of Producing letra-l .'ubstituted l rcas; and do hereby declare that the following is a full. clear, and exact description thereof.

This invention relates to a process of [Hilliinp; tetiasubstituted areas by the action of carbonyl chloride on a si'coi'idary amine dissolved in a. suitable organi solvent. and it pertains especially to such a process where in the reaction is carried out in the presence of a suitable basic material which will combine with the hydrogen chloride which is liberaterl as a result of the reaction between the carbonyl chloride and the secondary amine. More specifically, the new in'ocess comprises tr ating with carbonyl chloride a. secondary aromatic amine, such as methylaniline, dissolved in a liquid aromatic hydroearbon, such enzene. in the presence of another basic material, such as a tertiary amine.

It has been found that in treating a secondary amine. such as methylaniline, dissolved in benzene. with carbonyl chloride to form a tetra-substituted area. only ot' the methylaniline is converted into the area, the remaining 50%; combining with the hydrogen chloride which is liberated to form methylaniline hydrochloride which is in- :apahle of reacting with carbonyl chloride.

As is well known it is a diilicult matter to convert aniline into nionomcthylanilinc without etlecting a simultaneous conversion of part of the aniline (or part of the amine methylaniline) into diinethylaniline. In most of the methods for the preparation of mononiethvlaniline. therefore it is necessary to prepare a mixture of monomethylaniline and dimethydaniline which must subseipiently e resolved into its constit uents by chemical process s. Since it was found that Ilimcthylaniline docs not react apprw-iabli iih ar onyl chloride under the condition-s ol' the process. it was found possi le by adjhsting the conditions ot niethvlata- "l aniline toobiaii: :1 mixture Application filed September 11, 1918. 4 Serial No. 253,564,

of nionomethylaniline and dimethylaniline (together with small amounts of aniline) of such composition that the n'ionomethyb aniline could be practically completely converted into dinicthyhli 'ihenylurea, since the [IiiXtllic contained sufiicient dimethylaniline to combine with all the l'ltl formed in the reaction. This dimethylaniline can, of course be subserpiently recovered.

()no object of my invention is to provide a process whereby Substantially all of the secondary amine which is used may be converted into a tetra-sobstitutcd urea.

Another object of my invention is to avoid the necessity of isolating methylaniline in pure form in a process in which methyl aniline is to be converted into dimethyl d i phenylu rea.

Although the proportions of the materials used and the conditions under which the process is carried out are capable of wide variation. my invention may be illustrated by the following specific example.

A mixture of 100 parts of monomethylaniline and 112 parts of dimethylaniline is dissolved in llll) parts of benzene and warmed to about till (l. Carbonyl chloride in the form of a gas is then passed into the solution until all evidence of reaction has ceased. The benzene is then distilled oil and the residue is treated with dilute ll(.l for the complete removal of the (1iniethylaniline. The dimethyldiphenylurea is insoluble in the dilute acid. and may therefore be filtered otl' and washed free from acid with water. In order to complete the purification the product may be crysi llized from a suituble solvent.

The dimethylaniline may be substituted by any suitable basic material, suitable basic material being interpreted to mean a material which will dissolve in the solvent used. will combine with the Il(l formed in the reaction and will not react appreciably with carbonyl chloride under the conditions oi the process. lil1-lcdll oi hen/woe. any suit able organic solvent may be used. suitable organic solvent being interpreted to mean one which does not react with carbonyl chloride under the conditions of the process. such as carbon tetrachloride, toluene, Xylene,

lllfl tit) solvent naphtha, etc. As it is desired to avoid a reaction (condensation) lactwccn the secondary aniinc and the basic material. other substances tending t proniohsuch re action are excludcd.

1 claim 1- l. The process o producing: trtrawdr stitutetl areas which comprises trcating wlth carbonyl chloride in the jii'crit'lil't of a basic material a secondary amino ssolted in an inert organic solrenh said Secondary amine having its amino group attached to two by drocarbon radicals and said basic i'oaterial being soluble in the solvcnt need and capabie of combining with the irvdrogcn chlo ride formed during the reaction.

2. The process (it prodo in o; tUiltl-Silithii' tuted ureas which comprises treating a 0 ondary amine dissolved in an inert organic solvent with carbonyl chloride in the prcsence of a basic material and in the aliscnciof other substances capalil oi proniotiir; a reaction between thc basic material and the secondary amino said basic J'ililit'iiiii being soluble in the solvent nscd and capa ble of combining with the hydrogen chloride formed during the reactioni 3. The process of producing tctra-snbsti tuted areas which comprises treating with carbonyl chloride in the presence of a basic material a secondary amine dissolved in a liquid aromatic hydrocarbon. said secondary amine having its amino group attached to two hydrocarbon radicals and said basic material being aoluhle in the solvent used. and capable of combining withthe hydrogen chloride formed during the reaction.

4. The process of producing tetra-snbsti tuted areas which con'iprises treating with carbonyl chloride in the presence of a basic material a secondary aromatic amino dissolved in a liquid aromatic hydrocarbmn said secondary amine having its; amino roup attached to two hydrocarbon radicals, and said basic material bcing soluble in the solvent used. and capalllc of combining with the hydrogen chloride l'orincd tllll'lli; the reaction. and being present in sollicicnt quantity to combine with substantially all of the hydrogen chloride l'orincd din-in; t lt reaction.

5. The process of producing dimcth rlo phenylnrca which comprises passing ta bonyl chloride into a solution oF mcthrhur line and anothcr basic material in an inert organic solvent said basic material bcinn soluble in said solvent and capable of ('U[|I- llllllllg with the hydrogen chloride loriocd during the reaction. I

ti. The pro ess of producing tllll ltlllyltllphenylurca which compriscs passing car bonvl chloride into a benzene solution ol nictllvlanilinc and another basic material which will dissolve in the solvent used. oill combine with the hydrogen chloride i'orioed in thc rcaction and will not react appreciably with zarlion i hloride under the conditions ociaflio during: the process, the reaction living; tklll'li'il not at ancit-ratedtemperature.

T. 'lhc prim-as of producing tetra-subs itotcd urea. which romprisce inducing a reaction betuccn carbonyl chloride and a secndary amin in thc il-ltt-Hllt'tf ot a hlllli 'ltflll ipiahtity of a tertiary amine to react with aohsnoitiaily all th hydr agcn chloride formed during the rcactioin the reaction be in; brought about in the pres nce of an inert organic solrcnt tor the amines, and in the abscnrc of other substances tending to promote a reaction between said amines,

Isl The process of producing; tctrtrsuht-rtitilted llHilS which ci'mipriscs treating about ililllil molecular [)lOPUt'liUHS of a secondary and tcrtirirr amine dissolved in a liquid aromatic hydrocarbon with carbonyl chloride until the secondary amine has been converted into a term-substituted urea, and reparation" the resulting urea front the tertiar aniinc h drochloride which is formed.

5, The process of producing; tetra-substitutcd areas; which comprises treating about equal molccnlar proportions of a secondary aromatic amino and a tertiary amine dis-- solved in a liquid aromatic hydrocarbon with carbonyl chloride' until the secondary amine has been converted into a tetra-substituted nrezn and separating the resulting area from the tertiary amine hydrochloride which is formed.

to. The process of {)IUbltltllilg tetra-substitatcd areas which comprises treating about equal. molecular proportions of a secondary aromatic amine and in: tertiary amine dissolved in benzene with carbonyl chloride until the secondary amine has been convert cil into a tetra-5nbstitnted urea, and separating the resulting area from the tertiary amine hydrochloride which is formed.

11. The process of producing tetra-substituted areas which comprises treating about equal molecular proportions of an alhylarylamine and a tertiary amine dissolved in lienzine with carbonyl chloride untii the secondary amine has been converted into a tctra-subs itntcd urea, and separating the resulting urea from the tertiary amine hydrochloride which is formed.

iii The process of producing dialkyldiarrlorcas which comprises treating With cariiotryi' chloride an alkylarylamine, dissolved in an inert organic solvent in the presence of a sullicicnt quantity of a tlialkylarylamine to combine with substantially all of the hydrogen chloride formed in the reaction.

13. The process of producing: dialkyhliacvlurcas which comprises treating with carbonyl elllUIitlt an alkylanrlaminc, dissolved in at: cit organic solvent, in the presence oi a L icnt quantity of a dialkylarylamine to cooi inc with substantially all of the hydrogen chloride formed in the reaction, and maintainin the reaction mixture at a temperature 0 about 60 14. The )rocess of producing dialkyldiarylureas which comprises treating with carbonyl chloride an alkylarylamine, dissolved in a liquid aromatic hydrocarlmn, in the presence of a sufiicient quantity of a dialkylarylamine to combine with substantially all of the hydrogen chloride formed in the reaction.

15. The process of producing dimethyldiphenylurea which comprises treating with carbonyl chloride about equal molecular proportions of methylaniline and dimethylaniline dissolved in an inert organic solvent.

16. The process of producing dimethyldiphenylurea which comprises treating with carbonyl chloride about equal molecular proportions of methylaniline and dimethylaniline dissolved in a liquid aromatic hydrocarbon.

17. The process of producing dimethyldiphenylurea which comprises treating with carbonyl chloride about equal molecular proportions of methylaniline and dimethylani' line dissolved in a liquid aromatic.hydrocarbon, while maintaining the solution at a temperature of about 60 C.

18. The process of producing dinlethyldiphenylurea which comprises treating with carbonyl chloride about equal molecular proportions of methylaniline and dimethylaniline dissolved in benzene, whilemaintainin the solution at a temperature of about 60 19. The process of producing dimethyldiphenylur a which comprises passing carbonyl chloride into a solution heated to about (10 C. and containing one part of methylaniline, between one and two parts of dimet-hylaniline. and about one part of henzene until practically all evidence of reaction has ceased, distilling oil the benzene, and washing the residue with dilute hydrochloric acid to remove dimethylanilinc hydrm-hloride.

20. The process of producing tetra substituted areas which comprises treating a secondary alkyl-aryl-amine dissolved in an inert organic solvent with carbonyl chloride in the presence of a basic material which is soluble in the solvent used and is capable of combining with the hydrogen chloride formed during the reaction.

21. The process of producing tetra-substituted ureas which comprises inducing a reaction between a secondary amine, having an amino group attached to two hydrocarbon radicals, and carbonyl chloride in the pres .ence of a sutiicient quantity of a tertiary amine to react with substantially all of the hydrogen chloride formed during the reaction, said react-ion being brought about in the presence of an inert organic solvent for the amines.

In testimony that l claim the foregoing I have hereunto set my hand.

ARTHUR P. TANBERG.

Witnesses:

Hnuunn'r WINKEL, R. L. ANDREWS.

Certificate of Correction.

It is-herehy certified that in Lotlers Patent N u. 1,437,027, grnnlml Nnvmubm- 28, 1922, upon the application 0f Arthur I. 'ianhm-g, uf Wilmingthn Demwgu-o, for an improvement in lrucosscs of Producing 'lhu-zvfiuhstitutcd Ureas, an error appears in the printed spcifivnt-iun rvquiring uurrur-tinn' as fullmvs: Page 2, line 113, for the word bUHZiHU rcml brmarm': and that the said Letters Patent should he rem! with this curuecti on therein that the same may conform to the record uf the case in lhv Patent Ohice.

Signed and sealml [his 9th day of January, 1)., l923.

[sun] KARL FENNING, 

